Hi S., My grandson is like that with his mom. He would never think of sassing me or papa. My daughter became so frustrated she said nana and papa made him that way. I said wait a minute. We give him respsonsiblity and he owns up to his mistakes and takes his punishment like a man.
I told her to Give him responsibility not all chores. My grandson answers the phone for us and takes messages. This makes him feel important. We feed the birds together and lots of times we clean house together. We also go to movies and parks, theme parks, vacations together. He will load the car, pay for dinner with our money of course.
I guess what I am trying to say is instead of telling the child how wrong and bad he is we Nana and Papa praise him for good things and talk out the other habits or things that are not so good. Yes we have more time than most grandparents but this little guy will be taking care of us one day he needs to learn to be patient and compassionate.
NOw Mommy, daddy and son are on the road to fun times and son does not like to be sent to his room or asked to explain himself but he will. When he is talked to in a civil tongue and not belittled. Good lUck B.